Researchers and research groups in this area:
Description of the area:The research of the Inorganic Chemistry group involves both the synthesis and characterization of new coordination complexes as well as kinetic and mechanistic studies.
Bioinorganic Chemistry:
Bioinorganic chemistry is an interdisciplinary research area stemming from inorganic chemistry but with extensive overlap with both biochemistry and biophysics. The purpose of this research is to establish the roles metal ions play in biological systems, both good and bad.
Nature is dependent on a large number of metalloenzymes to catalyse the chemical transformations of organic substrates. The metal ion(s) is (are) usually the substrate's binding site and participates in its activation so it can undergo a specific reaction. Work at Odense University concentrates on the synthesis and characterization of "model" compounds for the active sites of metalloproteins/enzymes. The synthesis of model compounds involves the design and preparation of organic ligands appropriate for binding particular transition metal ions, often in a particular oxidation state. After complexation of the metal ion the properties, both spectroscopic and chemical, of these relatively small molecules are determined. Familiarity with the properties of these small molecules aids in the interpretation of spectroscopic and chemical properties of less well defined and much larger metalloenzymes. For example, it is well known that many transition metal complexes are colored and this color can often be related to the types and numbers of atoms that are bonded to the metal ion. Proteins often use amino acid side chains (e.g. histidine, cysteine, glutarimate, aspartate) to bind metal ions in a fixed geometry. Comparison of the electronic spectroscopic properties of the transition metal ion in situ with those of well-characterized models can give a good indication of which amino acid residues are used by a protein to bind a particular metal ion.
The metalloenzymes for which there is particular focus at Odense University include the electron transfer enzymes (Cu), the oxygen activation enzymes (Cu, Fe), the hydrolysis enzymes (Zn, Fe) and the O2 evolution complex in Photosystem II (Mn). A better understanding of Nature's use of transition metal ions in these metalloenzymes gives inspiration for the possible use of model compounds in performing similar tasks. There is a great interest in the use of peroxidases, ligneases and monooxidases or model compounds for these enzymes as "Synzymes" in chemical synthesis and certain technical processes, e.g. in paper production and detergents. Several "multinuclear" (molecules with more than one metal ion) iron and manganese compounds have been prepared at Odense University. Some have shown peroxidase, alkanoxidase and hydrolase activity. Part of the present research program concentrates on optimizing the catalytic activity of the systems via their chemical modification as well as the investigation of the reaction kinetics and the identification of reactive intermediates, e.g. crucial oxygen-atom transfer intermediates.
Kinetics and Reaction Mechanisms: Projects in this category can, in principle, involve many types of compounds, from both organic and inorganic chemistry. The purpose of investigating one or more reactions in solution is to understand the mechanism by which a chemical reaction occurs. Thus, to establish the type and structure of intermediates, and to reduce the total process into simpler, more elementary steps. Activity at Odense University has concentrated on mechanistic studies with the d8 transition metal ions Pd(II), Pt(II), Rh(I) and Ir(I). The relationship between the structure and electronic nature of complexes containing these metal ions and their rates of reaction has been studied. Several compounds showing unusually high substitution rates have been prepared. These complexes are of particular interest due to the extensive use of d8 transition metal ions in industrial catalysts.